Systems and methods for delivering heat in a battery powered blow dryer

ABSTRACT

A battery powered blow dryer having a novel heating element technology that can be powered by an attached battery pack. The heating element includes an infrared light bulb that emits high heat with relatively low power consumption compared to current methods. The present invention patent also describes a unique configuration of battery cells to optimally perform the task of blow drying hair.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Provisional PatentApplication No. 62/368,962, filed on Jul. 29, 2016, the contents ofwhich are incorporated herein by reference.

FIELD

This invention relates to the general field of hair dryers, andspecifically toward a unique battery powered blow dryer deliveringpowerful heat output, and more specifically to a battery-operated blowdryer utilizing new heating element technology that allows the blowdryer to be hot enough to style and dry hair but also be light enough tobe portable.

BACKGROUND

Blow dryers have been around for decades. For heating, the traditionalblow dryer uses a heating element made of a resistive wire (usuallynichrome) wrapped around an insulative core for shape (usually a micasheet). One example is shown in FIG. 1. As the dryer operates at variouslevels of power (e.g., high, medium, or low), varying amounts of currentrun through the resistive wire and the desired levels of heat output areachieved. This heating element construction is inexpensive, heats upquickly, and the power consumption can be fine-tuned by adjusting thelength or thickness of the wire. For these reasons, they have becomepopular in the overwhelming majority of hair dryers today.

The blow dryer also wastes a lot of heat because the heating element ispoorly insulated. FIG. 2 shows a thermal image of the casing of atypical commercial hair dryer in use under a thermal camera. While themajority of the power consumed by the dryer is due to the heatingelement, the figure shows that a significant portion of that power iswarming the casing of the dryer.

The blow dryer typically receives power transmitted through a cord thatis plugged into a wall outlet, limiting where the dryer can be used. Oneof the most significant technical barriers to implementing abattery-operated hair dryer is in supplying an adequate amount of power.Commercial hair dryers tend to fall in the 1600W to 2000W range, whichpresents challenges to power from a battery. A breakdown of thecomponents providing this power, shows that 10 to 20% of the powerconsumed is through the motor with the remaining amount drawn by theheating element. As a result, modifications to the heating elementpresent a significant opportunity to reduce the power consumption to thepoint where the device can be powered by a battery.

It would be desirable to develop a battery-operated blow dryer with aheating element design for low power consumption.

SUMMARY

The present invention is directed to a battery powered blow dryer havinga novel heating element technology that can be powered by an attachedbattery pack. The heating element includes an infrared light bulb thatemits high heat with relatively low power consumption compared tocurrent methods. The present invention patent also describes a uniqueconfiguration of battery cells to suitably perform the task of blowdrying hair.

In a first aspect, embodiments of the present invention provide abattery-operated hair dryer having a case having an air flow channelwith an air inlet and air outlet, a heating element positioned withinthe air flow channel between the air inlet and air outlet and powercontrol circuitry is coupled to the heating element configured toprovide one or more power optimization mode to the heating element. Afan assembly positioned within the air flow channel and at least onebattery configured to provide power to the power control circuitry andfan assembly. In use, the fan assembly draws in air through the airinlet, the air flows through the air flow channel and is blownover/through the heating element to heat the air, and the heated airexits through the air outlet.

In many embodiments, the battery-operated hair dryer further includesone or more resistive wires.

In many embodiments, the power optimization mode includes pulse widthmodulation (PWM) of the one or more infrared bulbs.

In many embodiments, the one or more power optimization mode includestime-delay heating circuitry to balance power between the infrared bulbsand resistive wires.

In many embodiments, the one or more power optimization mode includespower adjusting circuitry providing power to the resistive wires for afirst time period and/or set temperature reached, then adjusting thepower to the resistive wires.

In many embodiments, the battery-operated hair dryer further includes ahair temperature sensor coupled to the power control circuitryconfigured to detect a temperature of the hair and adjust the power tothe heating element when an ideal hair temperature is reached.

In many embodiments, the infrared bulbs are quartz tungsten bulbs.

In many embodiments, the resistive wires are nichrome wires.

In many embodiments, the battery is replaceable and/or rechargeable.

In many embodiments, the case includes a handle portion and the batteryis positioned within the handle portion. The handle portion may includeone or more air inlets configured to allow airflow over the batteryduring fan operation.

In another aspect, embodiments of the present invention provide anenergy efficient heating element system for a battery-operated hairdryer including one or more infrared bulbs and battery powered powercontrol circuitry coupled to the infrared bulbs configured to provideone or more power optimization mode.

In many embodiments, the heating element system further includes one ormore resistive wires coupled to the control circuitry.

In many embodiments, the power optimization mode includes pulse widthmodulation (PWM) of the one or more infrared bulbs.

In many embodiments, the one or more power optimization mode includestime-delay heating circuitry to balance power between the infrared bulbsand resistive wires.

In many embodiments, the one or more power optimization mode includespower adjusting circuitry providing power to the resistive wires for afirst time period and/or set temperature reached, then adjusting thepower to the resistive wires.

BRIEF DESCRIPTION OF THE DRAWINGS

The present embodiments may be understood from the following detaileddescription when read in conjunction with the accompanying figures. Itis emphasized that the various features of the figures are notnecessarily to scale. On the contrary, the dimensions of the variousfeatures may be arbitrarily expanded or reduced for clarity.

FIG. 1 shows a view of a prior art heating element.

FIG. 2 shows the heat signature of a prior art blow dryer.

FIG. 3 shows one embodiment of a battery powered blow dryer.

FIG. 4 shows an exploded view of the components of the battery poweredblow dryer.

FIG. 5 shows one embodiment of a heating element system.

FIG. 6 shows another embodiment of a heating element system.

FIG. 7 shows a coating on an infrared bulb.

FIG. 8 shows another embodiment of heating element system.

FIG. 9 shows a schematic of heating element system.

FIG. 10 shows one embodiment having the airflow flow around the batterycells.

FIG. 11 shows another embodiment of cooling the batteries.

FIGS. 12A-12F show different embodiments for arranging the one or morebatteries and electronics.

FIG. 13 shows one embodiment of the battery pack.

FIG. 14 shows the battery pack/handle.

FIG. 15 shows the battery powered blow dryer.

FIG. 16 shows an embodiment that the power cord plugged directly intoconnector.

FIG. 17 shows a heating ramp chart showing the different heat sources.

DETAILED DESCRIPTION

Embodiments of the invention will now be described with reference to thefigures, wherein like numerals reflect like elements throughout. Theterminology used in the description presented herein is not intended tobe interpreted in any limited or restrictive way, simply because it isbeing utilized in conjunction with detailed description of certainspecific embodiments of the invention. Furthermore, embodiments of theinvention may include several novel features, no single one of which issolely responsible for its desirable attributes or which is essential topracticing the invention described herein.

Prior attempts to provide enough heat to dry hair with a battery powereddryer have failed due to the high power consumption inherent inconventional heating elements. The present invention discloses a blowdryer that solves this problem by using a novel heating elementtechnology that provides a high level of heat with low power consumptionthat is powered by an internal battery. This unique combination allowsthe blow dryer to be hot enough to style hair but also be light enoughto be portable.

A powerful cordless blow dryer has numerous uses and benefits. Thefreedom of movement and high heat output that results from the use ofour novel heating elements can be used, of course, for styling anddrying hair in a more comfortable way, with no cords, and in locationsin which using a blow dryer was previously impossible. See some examplesbelow:

-   -   Grab-and-go styling around the house    -   Going downstairs to start the coffee machine    -   Moving out of the way of your spouse in the bathroom    -   Going to a mirror that is not fogged up by shower steam    -   Not fighting for a power cord plug    -   Caught in a rainstorm in a city, blow dry hair in taxi    -   One-handed grab while other the hand is occupied during        chores/errands    -   Cord doesn't reach desired location    -   Cord is tangled or no outlet is present    -   Men who blow dry their hair on the go    -   Locker room for sports teams or gym members    -   Fuse is blown or the electricity is out    -   In a rush for a dinner date, husband drives, wife finishes        blowing    -   “Girls weekend” in the car on the way to a resort.    -   “Girls weekend” in the cramped shared hotel bathroom    -   Glamping    -   Hair salons    -   On-location movie set stylists, “on-the-set”    -   Private aviation—styling on planes en route    -   Car services, limousines    -   On boats

FIG. 3 shows one embodiment of a battery powered blow dryer 100 having acase 105 with a handle 110, a heating element system 115, a fan 120positioned proximate the heating element 115, electronics 125 and one ormore batteries 130 positioned inside the handle 110 to power thecomponents. The case includes air flow channel with an air inlet 135 andair outlet 140. In the embodiment shown, the fan draws in air 145 athrough the inlet 135, the air 145 b flows through the case and is blownover/through the heating element to heat, and the heated air 145 c exitsthrough the outlet 140.

FIG. 4 shows an exploded view of the components of the battery poweredblow dryer 100. The heating element 115, fan assembly 120 andelectronics 125 are positioned inside the case. The case may be made inmultiple pieces, such as case 105 a and 105 b. The inlet 135 may includea screen 135 a and the outlet may include a screen or diffuser 140 a.

The battery may be integral or may be separate replaceable unit ormodule that can be charged/upgraded/swapped out separately from thedryer barrel. It is envisioned that different capacity batteries may beused to provide different price points. As a non-limiting example, thebattery unit may be composed of lithium ion cells or one or more lithiumpolymer pouches

In some embodiments, the battery may extend into the barrel or airchannel to conceal bulk.

In some embodiments, the barrel or air channel may be one-piece(seamless) plastic shell with components inserted from the back.

Heating Element

FIG. 5 shows one embodiment of a heating element system 115 a thatincludes an infrared bulb 150 a that is designed to operate in abattery-powered hair dryer to improve power consumption and allow thebattery powered blow dryer to function for a long duration and providemore heat than current dryers. The use of an infrared heating bulb toprovide a more effective transfer of heat from the dryer to the hairthan the nichrome wire element since it is able to heat the hair withoutwarming the air in between. This allows our heating element to drawlower power, in some embodiments, 600W.

FIG. 6 shows another embodiment of a heating element system 115 b thatincludes another type of infrared bulb 150 b that is designed to operatein a battery-powered hair dryer. To prevent heat from radiating inundesirable directions, the infrared bulb can be made into directionalbulb by painting the bulb 160 with a coating 165, such as a goldcoating, shown in FIG. 7. This technique can be leveraged in a hairdryer design to reduce waste heat that warms the casing of the dryer.

However, one of the downsides of an infrared bulb is that it takes alonger time to reach its peak temperature when compared to the resistivewire element. FIG. 17 shows the initial temperature warmup ramp for twoheat sources: 1) Nichrome; 2) IR bulb. In some embodiments, the bulb isbulkier than resistive wire and may restrict airflow through the outlet.As a result, a hybrid design that uses both heat sources may bedesirable.

FIG. 8 shows another embodiment of heating element system 115 c thatcombines an infrared bulb 150 c combined with a resistive wire component155 to provide steady state heat when the blow dryer is turned on. Thisis accomplished by powering the resistive wire component 155 to provideimmediate heat to the blow dryer while the infrared bulb 150 warms up.Once warmed, the infrared bulb 150 then provides the heat and theresistive wire component 155 may be then turned off. Alternatively, amix of resistive wire heating element and infrared (e.g., quartztungsten) can be used in tandem simultaneously. In one embodiment, theheating element consisted of 2×200W IR bulbs and 200W of nichrome wire.

FIG. 9 shows a schematic of heating element system 115 c, the heatingelement consists of 2×200W infrared bulbs 150 c, 1×200W nichrome wirecomponent 155, and some control circuitry 125. In tests, a dryer poweredby this heating element was able to heat a room-temperature surface(73.4° F.) to an average temperature of 112.4° F. from 6 inches away. A6000 mAh battery pack lasted 12 minutes in this configuration.

Techniques to Reduce Power

In its simplest form, the control circuitry 125 merely allows the dryerto operate in high/medium/low power modes. However, more advancedelectrical and physical techniques may be utilized for allow for poweroptimization.

Time-Delay Heating Circuitry

Since the infrared bulb can take 10s of seconds to reach its peaktemperature, it is desirable to have additional power devoted towardsthe nichrome wire component in the beginning to warm up the chamber andinfrared bulb. Once a cutoff time and/or temperature has been reached,the additional nichrome elements would be powered off. The specific timeand temperature could be fixed constants, or could be configurablethrough tunable user parameters.

This circuitry can be implemented in a cost-effective manner using an RCnetwork or 555 timer IC. For more complicated timing requirements, amicrocontroller can be used. The microcontroller approach may bepreferred if coupled with other enhancements that require morecomplicated calculations to be performed by the device to modulate theheat output.

Workaround for Batteries with Lower Peak Current Ratings

Typical lithium ion battery cells have two current ratings—continuousdischarge current, which defines how much current the cell can safelydischarge for prolonged periods of time, and peak discharge current,which defines how much current the cell can safely discharge for shorterbursts of time. Lithium ion cells that have high peak discharge currenttend to have lower capacity as a tradeoff, so it is desirable to find acell that has as low a peak discharge rate as possible while stillsatisfying the power requirements.

This limitation poses a problem for adding heating power when the unitis first powered on, since the current requirements could dictate ahigher peak current. However, by placing the nichrome wire in a coilaround the infrared bulb, a significant portion of the current budget(possibly all) could be directed to the nichrome wire when the unit isfirst powered on. This allows the wire to heat the chamber and infraredbulb for a certain amount of time, and then power could be switched tothe infrared bulb after the chamber has been heated by the nichrome.

Such a design would allow the benefits of the time-delay heatingcircuitry to be realized without requiring higher peak current in theinitial stages of operation.

Leveraging PWM for Controlling Heat Output

In the home lighting space, LED lighting has increased in popularityrecently due to the reduced power consumption compared to incandescentor fluorescent bulbs. However, unlike these other types of light bulbs,LEDs are inherently binary, meaning they can only be on or off. Thisposes a challenge from a home lighting perspective since the expectationis that many lights will be dimmable. One solution for this problem isto use a technique known as pulse width modulation (PWM). In PWM,instead of driving the LED with a constant voltage source over time, thevoltage source is on for a particular percentage of the time. Thiscauses the LED to flicker on and off at a rate indistinguishable to thenaked eye, with the duration of each state dependent on a measure knownas the duty cycle. A PWM signal with a duty cycle of 100% is on all ofthe time, where 75% would be on only 75% of the time, reducing theperceived brightness.

Using PWM and a frequency fast enough so the flicker isindistinguishable to the human eye, PWM can give the impression that anLED light is being dimmed, where in reality it is flickering on and offbetween completely on and off for a predetermined amount of time in eachstate.

Another common household circuit is the full wave rectifier. Modernpower plants transmit electricity in the form of alternating current(AC), while most consumer electronics operate off of direct current(DC). This is due to the fact that the properties of AC allow forgreater efficiencies in transmission, which the properties of DC makedevices more cost effective when the current travels a shorter distance.The full wave rectifier circuit converts AC power to DC.

One of the key components of the full wave rectifier is the outputcapacitor, which smooths the ripples in the input voltage out to anearly flat level. Without this smoothing, the output would be verynoisy and DC electronics would not be able to function.

In one embodiment, the infrared bulb shares properties similar to thecapacitor in the full wave rectifier circuit, and power consumption bythe heating element can be further reduced by using PWM. Current is onlydrawn from the battery in the “on” state of PWM, resulting in powersavings when the unit is in the “off” state. Since the infrared bulb hasinertia (similar to the capacitor in the full wave rectifier), it takessome time to cool down. This property can be exploited here to drive theLED with a PWM signal instead of constant voltage for power savings. Theinfrared bulb will smooth out the peaks and troughs of the PWM signal tosomething essentially constant from the end user's perspective.

To mitigate a severe drop in output temperature, the nichrome wire canbe connected to a constant voltage source since it does not exhibit asextreme inertial properties that the infrared bulb does.

Adding Sensor Technology for Reducing Excess Heat

Another property of the infrared heating bulb is that it heats thesurface it is pointed at without the air in between. As a result, thetarget temperature to reach depends not on the temperature of theheating element, but the remote temperature of the hair. By adding asensor such as a contactless infrared thermometer, the dryer can measurethe remote temperature of the hair and decrease the power output (e.g.,decrease the PWM duty cycle) when the ideal hair temperature has beenreached. Such a mechanism would be desirable from two standpoints: itwould prevent the dryer from damaging the hair, 2) it would reduce powerconsumption by providing a temperature ceiling which should not beexceeded.

Venting Battery Heat to Boost Output

Lithium ion battery cells heat when they are discharged. When the cell'scutoff temperature is reached, the cell can no longer discharge at thesame rate. FIG. 10 shows one embodiment having the airflow 170 flowaround the battery cells to reduce the surface temperature. In theembodiment shown, the fan draws in air 145 a through the inlet 135, theair 145 b flows around the battery cells and continue through the caseand is blown over the heating element to heat, and the heated air 145 cexits through the outlet 140.

As shown in the figure, the air is warmed or pre-heated by the batteryprior to reaching the heating element. If not designed into the dryer,this heat would become waste heat—heat that the batteries discharged toachieve, but not adding to the performance of the dryer. By using adesign that places the battery pack in line with the dryer's airflow,the battery heat can be drawn off the pack and fed into the heatingelement.

FIG. 11 shows another embodiment of cooling the batteries where thebattery case or handle includes 110 includes an intake vent 110 a andexhaust vent 110 b.

FIGS. 12A-12F show different embodiments for arranging the one or morebatteries 130 and electronics 125. As shown in the figures, there may bemultiple electronic circuit boards, such as printed circuit boards(PCB).

The batteries make up the bulk of the unit's weight, so they presentsome challenges in the overall product design. Since they are such asignificant portion of the overall weight, they need to be arranged inan ergonomic way.

Furthermore, they need to be connected electrically in a 6S2Pconfiguration. Although 2 stacks of 6 batteries would be ideal from anelectrical standpoint, the shape is unwieldy for a handheld dryer. Soother geometries have been considered. These other geometries requireelectrical connectors between the battery cells. These connectors addresistance (heat), so it becomes a balancing act to minimize waste heatwhile still achieving good ergonomics.

FIG. 12 shows many improved the configurations deemed to be feasiblegiven these constraints

Battery Pack

FIG. 13 shows one embodiment of the battery pack 130 as part of thehandle 110 that plugs into the casing 105 to form the blow dryer 100.The pack includes electrical connectors 170 that connect the batteriesto the electronics 125 and power the components. The bottom of the packmay include charging electric connectors 175 that may be used to chargeand recharge the batteries.

FIG. 14 shows the battery pack/handle 110 being assembled with thecasing 105. Also shown in the figure is a docking or charging station180 with charging connectors 185 and power cord 190 that interfaces withconnectors 175 to charge the batteries.

FIG. 15 shows the battery powered blow dryer 100 coupled to the dockingstation 180 to charge or store the unit.

FIG. 15 shows an embodiment that the power cord 190 is plugged directlyinto connector 175. This allows the blow dryer to be used while thebatteries are charging.

Other Uses or Applications for this Invention

This invention can be used as a portable heat and airflow source, notlimited to drying human hair. Defogging or defrosting glass: it acts asa portable fan or heater. For example, a DJ at a nightclub can use it toblow confetti off of the control panel, or a back country cat-skiingoperation can use it to warm the gloves of customers in between runs.

-   -   Military field operations.    -   Hunters and fisherman can use it to dry gear and clothing.    -   On a movie set, as part of special effects equipment to blow        things around.    -   Curing/drying paint or glue.    -   Dusting hard-to-reach areas.    -   Drying pets/livestock

The invention claimed is:
 1. A battery-operated hair dryer comprising: a case having an air flow channel with an air inlet and air outlet; a heating element positioned within the air flow channel between the air inlet and air outlet, the heating element including one or more infrared bulbs; power control circuitry coupled to the heating element configured to provide one or more power optimization mode to the heating element; a fan assembly positioned within the air flow channel; at least one battery configured to provide power to the power control circuitry and fan assembly, wherein the fan assembly draws in air through the air inlet, the air flows through the air flow channel and is blown over/through the heating element to heat the air, and the heated air exits through the air outlet.
 2. The battery-operated hair dryer of claim 1, wherein the one or more power optimization mode includes pulse width modulation (PWM) of the one or more infrared bulbs.
 3. The battery-operated hair dryer of claim 1, wherein the heating element further includes one or more resistive wires.
 4. The battery-operated hair dryer of claim 3, wherein the one or more power optimization mode includes time-delay heating circuitry to balance power between the infrared bulbs and resistive wires.
 5. The battery-operated hair dryer of claim 3, wherein the one or more power optimization mode includes power adjusting circuitry providing power to the resistive wires for a first time period and/or set temperature reached, then adjusting the power to the resistive wires.
 6. The battery-operated hair dryer of claim 1, further comprising a hair temperature sensor coupled to the power control circuitry configured to detect a temperature of the hair and adjust the power to the heating element when an ideal hair temperature is reached.
 7. The battery-operated hair dryer of claim 1, wherein the infrared bulbs are quartz infrared bulbs.
 8. The battery-operated hair dryer of claim 3, wherein the one or more resistive wires are nichrome wires.
 9. The battery-operated hair dryer of claim 1, wherein the at least one battery is replaceable and/or rechargeable.
 10. The battery-operated hair dryer of claim 1, wherein the case includes a handle portion and the at least one battery is positioned within the handle portion.
 11. The battery-operated hair dryer of claim 10, wherein the handle portion includes one or more air inlets configured to allow airflow over the battery during fan assembly operation.
 12. A battery-operated hair dryer comprising: a case having an air flow channel with an air inlet and air outlet with a handle portion; a heating element positioned within the air flow channel between the air inlet and air outlet, the heating element including one or more infrared bulbs and one or more resistive wires; power control circuitry coupled to the heating element configured to provide one or more power optimization mode to the heating element; a fan assembly positioned within the air flow channel; at least one battery replaceable and/or rechargeable positioned within the handle portion configured to provide power to the heating element, power control circuitry and fan assembly, wherein the fan assembly draws in air through the air inlet, the air flows through the air flow channel and is blown over/through the heating element to heat the air, and the heated air exits through the air outlet.
 13. The battery-operated hair dryer of claim 12, wherein the one or more power optimization mode includes pulse width modulation (PWM) of the one or more infrared bulbs.
 14. The battery-operated hair dryer of claim 12, wherein the one or more power optimization mode includes time-delay heating circuitry to balance power between the infrared bulbs and resistive wires.
 15. The battery-operated hair dryer of claim 12, wherein the one or more power optimization mode includes power adjusting circuitry providing power to the resistive wires for a first time period and/or set temperature reached, then adjusting the power to the resistive wires and infrared bulbs.
 16. The battery-operated hair dryer of claim 12, further comprising a hair temperature sensor coupled to the power control circuitry configured to detect a temperature of the hair and adjust the power output when an ideal hair temperature is reached.
 17. The battery-operated hair dryer of claim 12, wherein the handle portion includes one or more air inlets configured to allow airflow over the battery during fan assembly operation.
 18. An energy efficient heating element system for a battery-operated hair dryer comprising: one or more infrared bulbs; battery powered power control circuitry coupled to the infrared bulbs configured to provide one or more power optimization mode.
 19. The heating element system of claim 19, further comprising one or more resistive wires coupled to the control circuitry.
 20. The heating element system of claim 19, wherein the one or more power optimization mode is selected from the group consisting of: pulse width modulation (PWM); time-delay heating circuitry; and power adjusting circuitry providing power a first time period and/or set temperature reached, then adjusting the power. 